Liquid in Glass Thermometer Calibration Service

1 Page 1 NISTMeasurementServices: Liquid-In-Glass ThermometerCalibration Service NIST Special Publication 250-23 JacquelynWise U.S.DepartmentofCommerce NationalInstituteofStandardsandTechnology Open at page → 2 Page 2 CenterforBasicStandards TheCenterforBasicStandardsdevelopsandmaintainsthescientificcompetenciesandlaboratoryfacilitiesnec- essarytopreserveandcontinuetorefinethebasephysicalquantitiesuponwhichtheNation'smeasurement syste... Open at page → 3 Page 3 NISTMEASUREMENTSERVICES: Liquid-In-GlassThermometerCalibrationService JacquelynWise TemperatureandPressureDivision CenterforBasicStandards NationalMeasurementLaboratory NationalInstituteofStandardsandTechnology Gaithersb... Open at page → 4 Page 4 LibraryofCongressCatalogCardNumber:88-600580 NationalInstituteofStandardsandTechnology SpecialPublication250-23,128pages(Sept.1988) CODEN:XNBSAV U.S.GOVERNMENTPRINTINGOFFICE WASHINGTON: 1988 ForsalebytheSuperintendent of... Open at page → 5 Page 5 PREFACE Calibrations andrelatedmeasurement servicesoftheNationalBureauof Standardsprovidethemeansformakersandusersofmeasuringtoolsto achieve levelsofmeasurement accuracy thatarenecessary toattain quality,productivity and... Open at page → 6 Page 6 Thepresentpublication, SP250-23,NBSMeasurement Services:Liquid-in- GlassThermometer Calibration Service,byJacquelyn A.Wise, isoneof approximately 20documentsinthenewseriespublishedorinpreparationby theCenterforBasicStand... Open at page → 7 Page 7 TABLEOFCONTENTS 1.0DescriptionofService 1 1 .1General 1 1.2TypesofThermometersAcceptedforCalibrationatNBS... 1 1.3ProceduresForSubmittingAThermometer forCalibration . . 2 1.4ShippingInstructions 2 2.0DesignPhilosophyandT... Open at page → 8 Page 8 5.3.5BeckmannThermometers 33 5.3.6ClinicalStandardThermometers 35 5.3.7KinematicViscosityThermometers 35 5.3.8Low-temperatureThermometers 35 5.4Stem-temperatureMeasurement 36 5.5CheckingtheStandardPlatinumResistanceTherm... Open at page → 9 Page 9 10.0GlassChangesandRecalibration ofThermometers 115 10.1GlassChanges 115 10.1.1TemporaryChanges 116 10.1.2PermanentChanges 117 10.2Recalibration ofLiquid-in-GlassThermometers 118 11.0Future 119 12.0Bibliography 119 vii Open at page → 11 Page 11 1.0DescriptionofService 1.1General Thisserviceprovidescalibrations foravarietyofthermometers covering therangefrom-196to+538°C. Themajorityofthethermometers are liquid-in-glass butothertypesarecalibrated aswell;thermisto... Open at page → 12 Page 12 Anythermometer, suchasahouseholdthermometer, consistingofapaper, plasticormetalmountingcontainingthescalegraduationsandattachedto theunmarked glassthermometer bymetalclips, isnotacceptable for calibration. Maximumself-re... Open at page → 13 Page 13 NationalBureauofStandards Route270andQuinceOrchardRoad Gaithersburg, Maryland 20899 Attention: JacquelynWise Thermometerswillbereturnedviathemethodrequestedbythecustomer. If nopreference isstated,NBSwillselectabestmethod... Open at page → 14 Page 14 Thebulbofthethermometer isathinglass-walled reservoir forthe thermometer liquid. Itcontainsavolumeequivalent toaspecificnumber ofdegreesofthescaledependingupontheexpansioncoefficients ofthe thermometric liquidandthebulbg... Open at page → 15 Page 15 TOTALIMMERSION PARTIALIMMERSION COMPLETEIMMERSION Fig.2.Threewaysaliquid-in-glassthermometercanbeused. Apartial-immersion thermometer isdesigned toindicate temperatures correctlywhenthebulbandaspecifiedportionofthestemar... Open at page → 16 Page 16 Athermometer isdesignedtobeusedatonlyoneoftheaboveimmersion depthsanditisnormallycalibratedatthatdepth. Ifthethermometer is usedatimmersiondepthsotherthanthatatwhichitwascalibratedand intendedtobeused,thetemperaturereadi... Open at page → 17 Page 17 TABLE 1 TEMPERATUREEXPOSURELIMITSFORVARIOUSTHERMOMETERGLASSES [1] Strain ExposureLimits Point Continuous Intermittent °C °C °F °C °F Corningnormal7560 500 370 700 430* 805* KimbleR6 490 360 680 420 790 Jena16III 495 365... Open at page → 18 Page 18 intervals ordecimalmultiples andcanbereadincorrectly. Ifthe thermometers aregraduated in0.1or0.2degreeintervals (ordecimal multiples) ,everyfifthmarkshouldbelongerthantheintermediate ones andanumbershouldappearateveryten... Open at page → 19 Page 19 isalso0.4nun.Theminimuminnocaserepresentsgooddesign,andwell- designedthermometers willhavegraduation intervalsconsiderably larger thanthespecifiedminimum. Inorderforathermometer tobeusableovertheentirerangeofthescale , t... Open at page → 20 Page 20 13MM 5MM 10MM 10MM (GRADUATIONABOVEISLESSTHAN100°C) '30MM(GRADUATIONABOVEISGHEATERTHAN100°C) Fig.4.Minimumdistancesforscaleplacementonaliquid-in-glass thermometer . Anyauxiliaryscalemusthavegraduations identical tothoseo... Open at page → 21 Page 21 Because ofthe difficulties thatareencountered inthepractical realization oftheKTTS ,ithasbeennecessary todefineandutilize practical temperature scales. TheInternational Temperature Scaleand definingtextwasfirstadoptedin1... Open at page → 22 Page 22 Intherangeoftemperature normallycoveredbyliquid-in-glassthermo- metry,theIPTS-68isdefinedbythefollowingfixedpoints: (1)Theequilibrium between theliquidandvaporphases ofoxygen (condensation point ofoxygen atonestandard at... Open at page → 23 Page 23 Fig.5.StandardplatinumresistancethermometerandCutkosky ACresistance bridgeusedforcalibratingliquid-in- glassthermometers. Theconfiguration oftheresistor isinevitably theresultofcompromise betweenconflictingrequirements.... Open at page → 24 Page 24 Thehermeticsealthroughthesoftglassenvelopeatthethermometerhead hasbeenmadeusingshortlengthsoftungstenwire,totheendsofwhich platinumleadwiresarewelded. Theexternalplatinum leadsaresoft solderedtocopperleadsthataremechanic... Open at page → 25 Page 25 Thecalibrationbathsthatuseoilasthemediumareoperatedunderahood whichisisolatedfromtheventilationsystemofthebuildingandexhausted directlyoutside. Thethermometers submitted forcalibration andthestandardplatinum resistanceth... Open at page → 26 Page 26 4.2.1 IceBath Anicebath(seeFigure6)isafixed-pointapparatususedtodeterminethe referencepointonliquid-in-glassthermometers at0°C. Nostandard thermometer isneededtorealize thetemperature oftheiceandwater mixture. Ifitismade... Open at page → 27 Page 27 electrical orwaterproofadhesivetapeandenclosedinametalsleeveto protecttheoperator intheeventthatitshouldbreak. Theflaskis supportedbyastructurethatwillnotallowittotipovereasily. Aclip isplacedabovetheflasktoholdthethermo... Open at page → 28 Page 28 Fig.7.Steampointbath. suspended within this space. Watercondenses anddrips fromthe thermometer. Aprovisionismadebothforrelievinganyexcesspressurein thespacesurrounding thethermometers andfordetermining theexcess pressure... Open at page → 29 Page 29 00 EAM i 1 Hw COo w EnH O S3 H OS S3 !=»M H W $o H Pm a wo H CO S3w OH M< H <dM COQ S3 w i— l Q S3 O * U — s U CO M 1— 1 Pi OS HH WH a CO o ;< w H 00 ON ft 1 MH \J 0) O . i j rrt J-l Q) L> H CD rrt rj-< r 4 »-i 1 rrt rrt... Open at page → 30 Page 30 Fig.8.Schematicdrawingofthesteampointbath. Withabarometeraccurateto0.1mmmercury,thisprocedure iscapableof anaccuracyof0.002to0.003°C.TheFortintypebarometerwillusually sufficeforallbutthemostexactingmeasurements. 4.2.3Wat... Open at page → 31 Page 31 Fig.9.Oilbath. isforcedpasttheheatingcoils,throughthebottomopeningintothe largerwell,around thethermometers, andbackintothesmallerwell throughtheconnectingpassageatthetop. Forcalibration intherangeof+1to+95°C,distilledwa... Open at page → 32 Page 32 PULLEY BEARING INSULATION-^ HEATING COILS AIRSPACE SPACE BETWEEN TUBES BEARING THERMOMETER HOLDER INSULATION SUPPORT Fig.10.Drawingofwaterandoilbaths TwooilbathsaremaintainedatNBS .One,calledthelowtemperature oil bath,is... Open at page → 33 Page 33 theoillevelisfirstraisedtowithin25mmofthetopofthebathby handpumpingoilfromanoverflowcollection panunderthebath. As thermometers arecalibratedatthehighertemperatures, thebathoilwill expandandleavethroughtheoverflowtubeand... Open at page → 34 Page 34 V Fig.11 .Tinbath. 4.2.5Cryostat Calibrations from -1to-110 °Caremadeinthecryostat shownas Figure13.AverticalsectiondrawingisshownasFigure14.Thecryostat consistsofaninnerDewarflask,D,whichcontainsthebathliquid. This flas... Open at page → 35 Page 35 0 1020 STIRDRIVE Fig.12.Drawingoftinbath. heater coils, J,woundontheoutside ofthestirrer tube. The thermometers areimmersedinsidethestirrertube,thusshieldingthemfrom theheatercoils . Thebathliquidisafive-component mixtur... Open at page → 36 Page 36 Fig.13.Cryostat. usedasthebathmediumis2-methylpentane .Measuredgradients inthe cryostatdidnotexceed0.01°C.Theunknowntemperatureregionis25mm deep . 4.2.6LiquidNitrogenandLiquidOxygenPoints Acomparisonmeasurement canbemade... Open at page → 38 Page 38 Fig.15.Apparatususedtocalibratethermometers attheboiling pointofnitrogenandoxygen. 5.0OperationalProcedures 5.1ExaminationandPreparationofThermometers forCalibration Everythermometer submittedforcalibration isexaminedund... Open at page → 39 Page 39 dryiceisapproximately -78°C,andmercuryfreezesatapproximately -40°C,themercurywillsolidify. Thelowerhalfofthebulbiscooled andneverthestemormercurycolumn. Moderatetappingofthebulbona rubberpadorstopperorsimilarsoftspongyob... Open at page → 40 Page 40 Thethirdreasonforexaminingeachthermometerunderamicroscope isto Lookforforeignmaterialinthecapillaryanddefectsinthethermometer. Theforeignmaterials mostoftenfoundareglasschipsoroxidesof mercury. Theseobjectscanholdgasorme... Open at page → 41 Page 41 Ifathermometer issubmitted toNBSforcalibrationandthecalibration pointsarenotspecifiedonthepurchaseorder, itwillbetestedata referencepointandatintervalsofapproximately every100scaledivi- sions. IfitisanASTMthermometer, it... Open at page → 42 Page 42 Thesethermometers arecalibrated starting atthelowesttemperature requested andproceeding insequence tothehighest point. Ateach calibration point thethermometer mustbeimmersed deeper intothe calibrationbathtomaintainthepro... Open at page → 43 Page 43 5.3.4CalorimetricThermometers Insomecasesitisonlynecessary toaccuratelymeasure atemperature differenceratherthantheabsolutetemperature. Calorimetric thermometers weredesignedforthispurpose.Sincetheaccuracyofthesethermome... Open at page → 44 Page 44 TABLE3 SETTINGFACTORSFORBECKMANNTHERMOMETERS Foranyscalelengthupto15° Setting Factor Setting Factor 0°C 0.9935 55°C 1.0092 5 0.9951 60 1.0102 10 0.9967 65 1.0112 15 0.9984 70 1.0121 20 1.0000 75 1.0129 25 1.0014 80 1.013... Open at page → 45 Page 45 5.3.6ClinicalStandardThermometers Clinicalstandardthermometers areusedbythemanufacturers offever thermometers, whichareusedformeasuringbodytemperatures. Inthe UnitedStatestheyaremarkedindegreesFahrenheit witharangeof app... Open at page → 46 Page 46 minimizestheamountofliquidleftonthecapillarywall. Sufficienttime shouldalwaysbeallowed toassurecomplete drainage. Underadverse conditionsthismaytakeanhourormore. Inaddition togooddrainage characteristics, asatisfactory l... Open at page → 47 Page 47 oftheareasurrounding thebulb,whichisaisothemeantemperaturevalue oftheadjacent portion ofthethermometer stem. Stem-temperature measurements takenatNBSarebasedupontheuseoffadenthermometers wheneverpossible(seefigure19(b)).... Open at page → 48 Page 48 pieceoffoamisplacedatthebottomofthereentrantwell,enablingthe standardplatinumresistancethermometer tohavesomethingsoftonwhichto rest. Analuminumbushing,whichisapproximately 50mmlong,isplaced insideofthereentrantwellonthe... Open at page → 49 Page 49 bulb.) Thethermometer isgentlyplacedthroughtheholderandintothe regionofloosenedice. Ifthethermometer touchesafirmsurfacebefore itisimmersedtotheimmersionlineor0°Cmark,thethermometershould beremovedandtheiceloosenedfurthe... Open at page → 50 Page 50 15minutes,becausetheorganicfluidtendstoclingtothewallofthe capillary.) Whenstability isreached(themeniscusstopsmoving), the operatorgentlytapsthethermometer tofreeapossiblestickingmercury meniscusandrecordstheice-pointre... Open at page → 51 Page 51 5.8PlacementofFadenandAuxiliary Thermometers forMeasurementofStem Temperatures Fadenorauxiliarythermometers, ortheircombinations, areusedtomeasure themeanemergent-stem temperature fromtheimmersionlinetothetopof themercur... Open at page → 52 Page 52 n A I 209mm 'A I 78D*gr««s 15Dagraas i Fig.19(a).Measuringtheemergent-stemtemperatureofanASTM 33Cthermometerusingtwoauxiliarythermometers. 42 Open at page → 53 Page 53 I Fig.19(b).Measuringtheemergent-stem temperatureofanASTM 33Cthermometerusingtwofadenthermometers. 43 Open at page → 54 Page 54 At /K 20Degree* A I A 15Degrees Fig.20(a) .Measuringtheemergent-stem temperature ofanASTM 34Cthermometerusingoneauxiliarythermometer. 44 Open at page → 55 Page 55 Fig.20(b). Measuringtheemergent-stem temperatureofanASTM 34Cthermometerusingonefadenthermometer. 45 Open at page → 56 Page 56 cryostatandwaterbath,thetopofthebulborthetopofthecontraction chambermustbeimmersedaminimumof25mm.Intheoilbathsthebottom ofthebulbmustbeimmersed aminimumof76mmandthetopofthe contraction chamberimmersed aminimumof50mm. Int... Open at page → 57 Page 57 Fig.21(a).Measuringtheemergent—stemtemperatureofanASTM11C partial-immersion thermometerwiththeimmersionline belowthesurfaceofthebathmedium. 47 Open at page → 58 Page 58 1\ 156Degrees X 28.2Degrees si/ I RoomTemperature 0 25mm I 50mm Fig.21(b). Placementofauxiliarythermometersneededtoobtain dataforatoo-deepimmersioncorrection. 48 Open at page → 59 Page 59 sametemperature asthebulb. Because ofthe50mmregionofunknown temperature nearthetopoftheoilbathsanda76mmregionofunknown temperature nearthetopofthetinbath, afadenthermometer mustbe placedinthebathtodeterminethetemperature... Open at page → 60 Page 60 hi -7K 50mm 100mm V Fig.22.Measuringthetemperatureoftheportion ofatotal-immersion thermometerstemthat isintheunknown temperatureregionof theoilbathusinga100mmfadenthermometer. 50 Open at page → 61 Page 61 currentof1maisusedforthestandardplatinumresistancethermometer andtheamplification isadjustedsothatthevalueintheseventhdial (0.00001 fl)canbeseen. ThephaseisadjustedtozeroontheACbridge meter. Thephase/signal selectorswitc... Open at page → 62 Page 62 TABLE4 SAMPLEDATASHEET ROUTINEBATCHCALIBRATION READINGS NBSTESTNUMBER CK.STD. BRIDGESPRT TO Tl T2 T3 5 445 25.46480 -0.10 -0.10 +0.03 -0.11 25.46480 19.92 19.94 19.93 19.71 27.48504 19.93 19.95 19.93 19.71 510 515 39.90... Open at page → 63 Page 63 TABLE5 SAMPLEDATASHEET STEM-TEMPERATURE CORRECTIONS READINGS NBSTESTNUMBER T1 T5 T6 T7 ASTM33CASTM31CASTM11C 50MM 50MM 25MM IMMERSIONIMMERSIONIMMERSION CK.STDS. T8 T9 BRIDGESPRT 5 115 FADEN AUXILIARY 0.13 +0.5 +0.132 0.1... Open at page → 64 Page 64 TABLE6 SAMPLEDATASHEET ROUTINEBATCHCALIBRATIONCOMPUTATIONS NBSTESTNUMBER CK.STD. BRIDGE SPRT TO Tl T2 T3 5 445 25.46480 -0.10 -0.10 +0.03 -0.11 25.46480 R(TP)=25.46480 a +0.10 +0.10 -0.03 +0.11 f R(0)=25.46381 b 19.92 19... Open at page → 65 Page 65 wasderived frominformation given inNBSMonograph 126,Platinum ResistanceThermometry [13]andthearticle inMetrologia, TheInterna- tionalPracticalTemperatureScaleof1968AmendedEditionof1975[5]. Sincethederivationofthisfactori... Open at page → 66 Page 66 A= A= A= a(l+6/100) (0.003926378)*[1+(1.496448/100)] 0.0039851342 KnowingthevalueforAandthevaluet'atthetriplepointofwater,the factorusedtoconverttheR(TP)valuetotheR(0)valuecanbedetermined asshownbelow: R(TP)/R(0)=1+At' R... Open at page → 67 Page 67 TABLE7 ONEPAGEOFASTANDARDPLATINUM RESISTANCETHERMOMETERTABLE October17,1978,IPTS-68Table Temp. Resi^fcmrp J.11VC1 °C Ratio Diff . o 1000000-L•WWW 25078 1 1003986 250^86 2 1007971 25094 3 l!011955 251 !01 4 l'015938 251!0... Open at page → 68 Page 68 R(t)/R(0)=1.079379 R(t)/R(0)at19°C=1.075531 Difference=0.003848 DecimalValue=Difference*Inverse Difference Decimalvalue=(0 .003848)*(252 .33) Decimalvalue=0.97 Thecalculatedtemperatureofthecalibrationbathatthefirstcalibr... Open at page → 69 Page 69 .20 I Uncertainty .10 c o o a> i— l_ o O .00 1Scale Division 0 20 40 60 80 100 Temperature°C Fig.23.Thermometercorrectionversustemperature. forliquid-in-glass thermometers. Ifthesedataweretakenbytwo observers, theprobabi... Open at page → 70 Page 70 n=numberofscaledegreesequivalent tothelengthofemergent stem(includingtheevaluatedregionabovetheimmersionline) t obs =observedmeantemperatureoftheemergentstem(Fadenor auxiliarythermometerreading) t sp =specifiedmeantemper... Open at page → 71 Page 71 TABLE8 VALUESOFTHEDIFFERENTIALCOEFFICIENTOFCUBICALEXPANSION OFMERCURYINGLASS(k)FORMERCURY-IN-GLASSTHERMOMETERS Table8(a) MeanTemperature k k (ti+t)/2 "Normal"Glass "Borosilicate" Glass ForCelsiusThermometers 0° 0.000158... Open at page → 72 Page 72 TABLE9 NBSTESTNUMBER T4 T5 T6 T7 ASTM33CASTM34CASTM11C 50ran 50ran 25run IMMERSIONIMMERSIONIMMERSION -K3.U3 +0.5 - .5 .0 -0.43 SAMPLEDATASHEET STEM-TEMPERATURE CORRECTIONS COMPUTATIONS CK. T8 STDS. T9 -0.5 +0.132 +0.1* -... Open at page → 73 Page 73 100.52 100.40 t=100.15°C35,47688 100.52 100.10 698 707 -.37 -.25 R(t)=35.17698 R(t)/R(0)=1.393231 150.1 148.82 t=148.39°C40.19077 103rrm 100nm 150.1 148.82 096 112.9 140.0 -1.7 -.43 106 +.6 0.0 +1.7 e -.03 R(t)=40.19093... Open at page → 74 Page 74 Thefourthvalueisthespecifiedaveragetemperatureoftheemergentstem (t sp ).Thisvalueisthetemperaturethattheemergentstemshouldbe. If thethermometer isatotal-immersionthermometerhavingaportionofthe stemoutofthemediumbeingmeas... Open at page → 75 Page 75 TABLE10 FADENTHERMOMETERCORRECTIONS FadenThermometerLength 100mm 103mm 114mm 200mm Ice-Point Correction 0.0 +0.6 +0.9 +1.0 ScaleCorrection Temperature °C 0 0,0 0.0 0.0 0.0 50 +0,.1 -1.0 -2.1 -0.3 100 +1..2 -1.0 -2.4 +0.2... Open at page → 76 Page 76 Calculating thestem-temperature correctionafterthetemperature ofthe emergentstemisdetermined isidenticalwiththeonediscussedinSection 6.3.1. Thecalculation isgivenbelow: EmergentStem-temperaturecorrection=kn(t obs -t sp )... Open at page → 77 Page 77 6.3.5Too-deepImmersionCorrection Sometimes itisnecessary toimmerseapartial-immersionthermometerwith theimmersionlinebelowthesurfaceofthebathmedium. Thiswillbethe caseifthedistancefromtheimmersionlinetothebottomofthetherm... Open at page → 78 Page 78 Ifthecomputedcorrection ispositive, itisaddedtothethermometer correction. Ifthecomputedcorrection isnegative, itissubtractedfrom thethermometer correction. Theresultingcorrection isapplicablewhen thisthermometer isusedat... Open at page → 79 Page 79 tableisgiveninTable8(b),wherethevalueofkcorresponding tothe bathtemperatureandfadenthermometerreadingcanbeeasilydetermined. ThevalueLBisequivalent ton,asdiscussed inSections6.3.1thru 6.3.4. Thisvariationoftheformula isus... Open at page → 80 Page 80 6.3.8EmergentStem-temperatureCorrectionforBeckmannThermometers Beckmannthermometers arealsocalibrated attotalimmersion, butmaybe usedatpartial immersion. Theformulausedtocompute theemergent stem-temperature correction is... Open at page → 81 Page 81 U.S.DEPORTMENTOFCOMMERCE NOTIONALBUREAUOFSTANDARDS NATIONALMEASUREMENTLABORATORY GAITHERSBURG,' MD.£0899 REPORTOFCALIBRATION LIQUID-IN-GLASS THERMOMETER. TESTEDFOR:NATIONALBUREAUOFSTANDARDS DIVISION522 MARKED:SURETYTO RA... Open at page → 82 Page 82 PAGE£ THETABULATEDCORRECTIONSAPPLYPROVIDEDTHEICE-POINTREADING,TAKEN AFTEREXPOSUREFORNOTFEWERTHAN3DAYSTOATEMPERATUREOFABOUT23 DEGREESC(73DEGREESF),IS-0.10C .IFTHEICE-POINTREADINGISFOUND TOBEHIGHER(ORLOWER)THANSTATED,ALLOT... Open at page → 83 Page 83 1)Company,agency,orestablishment thatsubmitted thethermometer, 2)Manufacturer's tradenameandserialnumberofthe thermometer , 3)Rangeandgraduationinterval, 4)Calibrationtemperaturesandcorrections, 5)Temperaturescaleused(IP... Open at page → 84 Page 84 CORRECTIONFOREMERGENTSTEM Thisstemcorrectionsheetisdesigned toexplain theprocessofcomputingthecorrectionsforemergent stem,buthasnotbeenspecificallyadaptedtothe individualthermometerwithwhichitisissued. Ifatotal-immersion... Open at page → 85 Page 85 DIFFERENTIALCORRECTIONFOREMERGENTSTEM Thissheetisdesignedtoexplainaconvenientprocess ofcomputingthedifferentialcorrectionforemergent stembutliasnotbeenspecificallyadapted tothe individualthermometerwithwhichitisissued. I... Open at page → 86 Page 86 heatedtoahighertemperature, anerroror0.01°Corless,foreach10 degreedifferencebetweenthetwotemperatures, maybeintroduced. The tabulatedcorrections applyifthethermometer isusedinitsupright position; ifusedinahorizontalposit... Open at page → 87 Page 87 Thissheetgivesatableofsettingfactorsandanexampletoexplaintheprocesses employed incalculations.Theexample,however,hasnotbeenspecificallyadaptedtothe individualthermometerwithwhichthissheetisissued. Thethermometer issaidto... Open at page → 88 Page 88 Othernotesthatareoccasionallyusedandareselfexplanatoryaregiven below: Thisthermometer complieswiththeaccuracyrequirement oftheapplicable ASTMspecification totheextentofthetestsmade. Thisthermometer doesnotcomplywiththeac... Open at page → 89 Page 89 thefirstandthirdplatinumresistancethermometervaluesforthefirst liquid-in-glass thermometer. Checkanyfadenorauxiliary thermometer readingsforcorrectness. 8.1UseofCheckStandards Theabovesourcesoferrorcanbepracticallyelimin... Open at page → 90 Page 90 TABLE11 RECORDOFCHECKSTANDARDCORRECTIONS ThermometerSerialNumber 274762 DATE 3/26/76 3/29/76 4/1/76 4/6/76 4/21/76 5/17/76 5/25/76 BOOK F115 C193 C193 C193 G30 C194 F115 PAGE 182-83 169 173 174-75 192-93 2 188 Temp. Corr... Open at page → 91 Page 91 onthecheckstandardtobeabletotellwhetheritisthenewortheold valuethatisout-ofcontrol. Lackofagreement isalwaystakenasan indicationofaproblemwiththecurrentcalibration, andcalibrations on allthermometers inthegrouparerepeate... Open at page → 92 Page 92 TABLE12 TOLERANCESANDUNCERTAINTIES FOR LOW-TEMPERATURETOTAL-IMMERSION THERMOMETERS Temperature Typeof Graduation Toler- Uncertainty rangein thermometer intervalin ancein indegrees degrees degrees degrees Celsiusthermomet... Open at page → 93 Page 93 TABLE13 TOLERANCESANDUNCERTAINTIES FOR LOW-TEMPERATUREPARTIAL-IMMERSION THERMOMETERS Temperature rangein degrees Typeof thermometer Graduation intervalin degrees Toler- ancein degrees Uncertainty indegrees Celsiusthermom... Open at page → 94 Page 94 TABLE14 TOLERANCESANDUNCERTAINTIES FOR CELSIUSTOTAL-IMMERSION MERCURYTHERMOMETERS Temperaturerangein degrees Graduation intervalin degrees Tolerance in degrees Uncertainty indegrees Thermometersgraduatedunder150°C 0upto1... Open at page → 95 Page 95 TABLE15 TOLERANCESANDUNCERTAINTIES FOR FAHRENHEITTOTAL-IMMERSION MERCURYTHERMOMETERS Temperaturerangein degrees Graduation intervalin degrees Tolerance in degrees Uncertainty indegrees Thermometersgraduatedunder300°F 32u... Open at page → 96 Page 96 TABLE16 TOLERANCESANDUNCERTAINTIES FOR CELSIUSPARTIAL-IMMERSION MERCURYTHERMOMETERS Temperaturerangein degrees Graduation intervalin degrees 3 Tolerance in degrees Uncertainty indegrees 13 Thermometersgraduatedunder150°C... Open at page → 97 Page 97 TABLE17 TOLERANCESANDUNCERTAINTIES FOR FAHRENHEITPARTIAL-IMMERSION MERCURYTHERMOMETERS Temperaturerangein degrees Graduation intervalin degrees 3 Tolerance in degrees Uncertainty indegrees 13 Thermometersgraduatedunder30... Open at page → 98 Page 98 reason. Therefore, increasing thelengthofadegreeonthescale,for practicalbulbsizes,improvesthermoraetric performance onlytoacertain point. Beyondthispointprecisionofreadingmayreadilybemistakenfor accuracyintemperature mea... Open at page → 99 Page 99 Overthepastsixteen years, fourteen liquid-in-glass thermometers, representing themostaccuratetypesinagiventemperature range,have beenusedascheckstandards. Twototal-immersionthermometers ofeach typewerechosenforthestandar... Open at page → 100 Page 100 madeforthebulbvolumechange. Allofthedatawerenormalized toa constant ice-point readingrepresenting anapproximate averageofthe ice-pointcorrections. Thedataforselectedpointswereagainplottedand theresultsaregiveninFigures29... Open at page → 101 Page 101 0.00 YEAR Fig.29(a) Plot forthermometer, serial number T531432, atfive temperatures (1at32°F,2at-30°F,3at-40°F,4at -50°F,and5at-60°F) .Thereadingswerenotcorrectedfor ice-pointshifts. 0.00 -0.05- -0.10 -0.IS - -0.20 - -0.... Open at page → 102 Page 102 0.00 72 73 74 75 76 77 78 79 80 81 YEAR Fig.30(a). Plot for thermometer, serial number T531438, attive temperatures (1at32°F, 2at-30°F,3at-40°F,4at -50°F,and5at-60°F) .Thereadingswerenotcorrectedfor ice-pointshifts. 72 7... Open at page → 103 Page 103 0.18 0.16 0.14 S0.12 0.10 0.08 0.06 YEAR Fig.31(a). Plot for thermometer, serial number 274762, at six temperatures (1at0°C,2at10°C,3at20°C,4at30°C,5 at40°C,and6at50°C) .Thereadingswerenotcorrected forice-pointshifts. 0.... Open at page → 104 Page 104 0.20 0.18 0.16 0.14 0.12- 0.10 72 74 76 78 80 82 YEAR 32(a) u LU a. <Y a u cc UJ I- Lu E o a. LU I H Plot for thermometer, serial number 275764, at six temperatures (1at0°C,2at10°C,3at20°C,4at30°C,5 at40°C,and6at50°C) .T... Open at page → 105 Page 105 0.04 -0.04 | I I I I | I I I I | I I I I | I I I I | I I I I 72 73 74 75 76 77 YEAR Fig.33(al).Plot for thermometer, serial number 4030424, atfour temperatures (1at0°C,2at50°C, 3at60 ° ,and4at 70°C) .Thereadingswerenotco... Open at page → 106 Page 106 u o .100 .075 .050 .025 .000 7025 7G 77 33(b) Plot forthermometer, serial number 4030424, atthree temperatures (1at0°C,2at70°C,and3at100°C) .The readingswerecorrectedforice-pointshifts. 0.01 0.00 -0.01 o |-0.0E -0.03 34(... Open at page → 107 Page 107 0.08 0.06 0.04 0.02 0.00 -0.03 Fig.34(a2) YEAR Plot forthermometer, serial number 4030425, atthree temperatures (1at80°C,2at90°C,and3at100°C) .The readingswerenotcorrectedforice-pointshifts. .075 .050 .025 ,000 -025- -05... Open at page → 108 Page 108 ijJ 0.2 0.1 0.0 0.1 -0.2 35(al) u LU or <r a u a. LU h- lll £ o £ LU X Plotforthermometer, serialnumber48425,atsixtemperatures (1at0°C,2at10°C,3at20°C,4at30°C,5at40°C, and6at50°C) .Thereadingswerenotcorrectedforice- poin... Open at page → 109 Page 109 0.le -0. 15— J 1 1 1 1 1 1 1 76 78 80 82 84 35(a2).Plot for thermometer, serial number 48425, at five temperatures (1at60°C,2at70°C,3at80°C,4at90°C, and5at100°C) .Thereadingswerenotcorrectedforice- pointshifts. 0.05-1 1... Open at page → 110 Page 110 0.30 77 78 79 80 81 82 83 84 VEPR 36(al).Plot for thermometer, serial number 198694, at six temperatures (1at0°C,2at10°C,3at20°C,4at30°C,5 at40°C,and6at50°C) .Thereadingswerenotcorrected forice-pointshifts. 77 78 79 80 8... Open at page → 111 Page 111 0.12 0.10 0.08 YEAR 36(b). Plot for thermometer, serial number 198694, atthree temperatures (1at0°C,2at40°C,and3at90°C) .The readingswerecorrectedforice-pointshifts. -0.1 -0.5 37(al).Plot for thermometer, serial number,... Open at page → 112 Page 112 o -0.35 -0.40 -0.45 -0.50 -0.55 -0.60 37(a2) Plot for thermometer, serial number 382213, at six temperatures (1at150°C,2at160°C,3at170°C,4at 180°C,5at190°C,and6at200°C) .Thereadingswerenot correctedforice-pointshifts. -0... Open at page → 113 Page 113 0.0 72 74 76 78 80 82 84 YEAR 38(al).Plot for thermometer, serial number 382215, at six temperatures (1at0°C,2at100°C, 3at110°C,4at 120°C,5at130°C,and6at140°C) .Thereadingswerenot correctedforice-pointshifts. -0.2 72 74... Open at page → 114 Page 114 -0. 1 -0.2 -0.3 -0.4 -0.5 Fig.38(bl).Plot for thermometer, serial number 382215, atthree temperatures (1at0°C,2at100°C,and3at200°C) .The readingswerecorrectedforice-pointshifts. -0.20 -0.E5 -0.30 -0.35 -0.40 -0.45 -0.50... Open at page → 115 Page 115 0.1 0.0 -0.1 -0.2 -0.3 Fig.39(al) Fig.39(a2) Plot forthermometer, serial number T1124411, atfive temperatures (1at0°C,2at200°C, 3at210°C,4at 220°C,and5at230°C) .Thereadingswerenotcorrectedfor ice-pointshifts. 0.30 0.25 0... Open at page → 116 Page 116 0.25 0.20 0.15 0.10 0.05 YEAR Fig.39(b). Plot for thermometer, serial number T1124411, attwo temperatures (1at0°Cand2at250°C) .Thereadingswere correctedforice-pointshifts. or tr a u <r HI h- £ a E ir uj r 0.2 0.1 0.0 -0.... Open at page → 117 Page 117 0.35--- 0.15 Fig.40(a2).Plot for thermometer, serial number T1124412, atsix temperatures (1at250°C,2at260°C,3at270°C,4at 280°C,5at290°C,and6at300°C) .Thereadingswerenot correctedforice-pointshifts. 0.25 0.20 0.15 W 0.10... Open at page → 118 Page 118 1.0 -1.5 41(al).Plot for thermometer, serial number 234453, atfour temperatures (1at0°C,2at300°C,3at310°C,and4at 320°C) . Thereadings werenotcorrected forice-point shifts . -0.75- -1.00 -1.25 g-1.50 1.75 -2.00 YEAR 41(a2... Open at page → 119 Page 119 0.5 41(b). Plot for thermometer, serial number temperatures (1at0°Cand2at350°C) . correctedforice-pointshifts. 234453, at two Thereadingswere 42(al).Plot for thermometer, temperatures (1at0°C 330°C,and5at340°C) . ice-poi... Open at page → 120 Page 120 -a. s 74 76 78 80 83 TEAR Fig.42(a2).Plot for thermometer, serial number 234456, atfive temperatures (1at350°C,2at360°C,3at370°C,4at 390°C,and5at400°C) .Thereadingswerenotcorrectedfor ice-pointshifts. Acomparisonofthecal... Open at page → 121 Page 121 TABLE20 LIMITSTORANDOMERRORCOMPUTEDFROMCHECKSTANDARDMEASUREMENTS Temperature Range (°F) Bath Temperature (°F) Check Standard Number Limitto RandomError (3Standard Deviation) Degreesof Freedom 60to-30 -30 -40 -50 -60 -30... Open at page → 122 Page 122 Temperature Range (°C) 0to100 Bath Temperature Check Standard Limitto RandomError Degreesof Freedom 100to200 ( °C) Number (3Standard Deviation) 10 48425 .030 22 20 48425 .031 44 30 48425 .036 38 40 48425 .025 42 50 48425... Open at page → 123 Page 123 Temperature Range CO 200to300 Bath Temperature CO 200 210 230 250 270 300 210 240 250 260 270 290 300 Check Standard Number T112411 T112411 T112411 T112411 T112411 T112411 T112412 T112412 T112412 T112412 T112412 T112412... Open at page → 124 Page 124 TABLE22 CALCULATEDUNCERTAINTIES FORLIQUID-IN-GLASSTHERMOMETERS Temperature Range (°F) -60to-30 Thermometer Graduation (°F) 0.2 Limitto RandomError (3a) 0.054 Total Systematic Error 0.029* Calculated Uncertainty 0.083 Tem... Open at page → 125 Page 125 fluidclingstothecapillarywallastheliquidrecedesintothebulb. Becauseofthisthethermometer shouldnotbereadimmediately after insertion intothemedium. Uptoonehourmightberequiredbeforea readingcanberecorded. Datawillhavetobeta... Open at page → 126 Page 126 closeapproachtoquasiequilibriummaybereachedintheorderofhoursat annealingtemperatures, whileinfinitetimemayberequiredatmuchlower temperatures . Ifaglassthathasbeenheatedtoahightemperature isallowedtocool rapidly, itwillbe... Open at page → 127 Page 127 measureagiventemperature, itwillindicateanerroneously lowvalueif ithas,withinashortperiodoftime,previouslybeenexposedtoahigher temperature. Withthebettergradesofthermometric glassestheerror resultingfromthishysteresiswil... Open at page → 128 Page 128 10.2Recalibration ofLiquid-in-GlassThermometers Thethermometer scalecorrectionsquotedintheNBSReportofCalibration applyaslongastheice-pointreadingremainsthesameasobservedduring thecalibration. Asdiscussedabove,subsequentc... Open at page → 129 Page 129 currentsetofcorrections forthethermometer (seeNBSMonograph150[7], Section4).Aliquid-in-glassthermometerwillneverhavetobereturned toacalibrationlaboratory, suchasNBS,forrecalibration . 11.0Future Thedemandforliquid-in-gla... Open at page → 130 Page 130 Ween,Sidney,"TheBeckmannDifferentialThermometer: ItsPrinciples ofConstruction andApplication," MaterialsResearchandStandards, MTRSA,Vol.12,No.8,August1972,p.31. Buckingham, E. ,Thecorrection foremergentstemofthemercurial... Open at page → 131 Page 131 NBS-114A(REV.2-8C) U.S.DEPT.OFCOMM. BIBLIOGRAPHICDATA SHEET(Seeinstructions) 1.PUBLICATIONOR REPORTNO. NIST/SP-250/23 2.PerformingOrgan.ReportNo 3.PublicationDate September1938 4.TITLEANDSUBTITLE Liquid-In-Glass Thermome... Open at page → 135 Page 135 THESP250SERIESONNISTMEASUREMENTSERVICES* SP250-1 SpectralRadianceCalibrations SN003-O03-02792-8 $3.50 SP250-2 FarUltravioletDetectorStandards PB87227609 SP250-3 RadiometricStandardsintheVacuum Ultraviolet SN003-003-02806... Open at page → 136 Page 136 U.S.DepartmentofCommerce NationalInstituteofStandardsandTechnology (formerlyNationalBureauofStandards) Gaithersburg,MD20899 OfficialBusiness PenaltyforPrivateUse$300 MlOP StimulatingAmerica'sProgress Open at page →